Experimental results on fluctuations of conserved charges confronted with predictions from canonical thermodynamics

Abstract

The study of multiplicity distributions of identified particles in terms of their higher moments is at the focus of contemporary experimental and theoretical studies. In a thermalized system, combinations of these moments are directly related to the Equation of State (EoS). The ultimate goal of the experimental measurements in relativistic nuclear collisions is, by systematic comparison to QCD and QCD inspired calculations, to probe the dynamics of genuine phase transitions between a hadron gas and the quark-gluon plasma. However, the comparison between experiment and theory is far from trivial, because several non-dynamical effects on fluctuations need to be controlled prior to a meaningful comparison to theoretical predictions. In this report we present quantitative estimates for these non-dynamical contributions using the Canonical Ensemble (CE) formulation of statistical mechanics. Together with analytical formulas we provide also results from Monte Carlo (MC) simulations within the CE and compare our predictions with the corresponding measurements from the STAR experiment.

References in corpus (6)

• The chiral and deconfinement aspects of the QCD transition
• Fluctuations as probe of the QCD phase transition and freeze-out in heavy ion collisions at LHC and RHIC
• Baryon number conservation and the cumulants of the net proton distribution
• Bridging the gap between event-by-event fluctuation measurements and theory predictions in relativistic nuclear collisions
• Energy Dependence of Moments of Net-Proton and Net-Charge Multiplicity Distributions at STAR
• Net-baryon fluctuations measured with ALICE at the CERN LHC

Cited by in corpus (13)

• 50 Years of Quantum Chromodynamics
• Relativistic nuclear collisions: Establishing a non-critical baseline for fluctuation measurements
• Proton number fluctuations in $\sqrt{s_{NN}}$ = 2.4 GeV Au+Au collisions studied with HADES
• Global baryon number conservation encoded in net-proton fluctuations measured in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Multiplicity dependence of (multi-)strange baryons in the canonical ensemble with phase shift corrections
• Binomial acceptance corrections for particle number distributions in high-energy reactions
• The imprint of conservation laws on correlated particle production
• Closing in on critical net-baryon fluctuations at LHC energies: cumulants up to third order in Pb$-$Pb collisions
• A model-free procedure to correct for volume fluctuations in E-by-E analyses of particle multiplicities
• Deciphering the phases of QCD matter with fluctuations and correlations of conserved charges
• Isolating dynamical net-charge fluctuations
• Overview of fluctuation and correlation measurements
• Net-proton number fluctuations in the presence of the QCD critical point